O.J. Simpson should have told jurors five years ago that he was hammered on Bloody Marys and Jack Daniel’s before leading armed thugs into a hotel-room robbery, his legal team said today.

Simpson — seeking to have his 2008 conviction for armed robbery tossed — testified in Vegas yesterday that he had been drinking heavily on Sept. 13, 2007, the day he and buddies held up two sports memorabilia dealers at the Palace Station Hotel & Casino.

The Juice said he skipped a morning tee time that day and by “midday, I went down and had a late breakfast, had a Bloody Mary or two.”

O.J. said he kept drinking Jack Daniel’s on the rocks later that day was O.J.’s preferred cocktail of the day, he said.

By nightfall and his confrontation with memorabilia collectors, Simpson said he was in no condition to drive.

“I think I hold my liquor pretty well. I’m not a fall- down drunk . . . [but] I wouldn’t get behind the wheel of a car,” said Simpson, who did not testify at his 2008 trial.

“I knew I could not pass a test if I were caught driving.”

Simpson, 65, is claiming that shoddy work by former defense lawyer Yale Galanter led to his conviction and a 33-year prison sentence.

The Juice’s current lawyer, Patricia Palm, hinted today that Simspon’s boozing should have played a key role in his 2008 defense.

“Did they [former defense lawyers] ever tell you it’s [heavy drinking] a possible fact that you … could use as your defense?” Palm asked.

“Absolutely not,” Simpson responded.

Simpson shuffled into the Clark County courtroom of Judge Linda Bell, wearing his dark blue prison uniform with handcuffs and a chain around his waist. He was also shackled at the ankles.

Court security un-cuffed Simpson’s right hand, which he used to pour himself water and gesture throughout his testimony.

Simpson was alert, animated and occasionally glib for his day-long testimony.

Courtroom spectators laughed when Simpson explained how helpful some of his legal-savvy neighbors at Lovelock Correctional Facility have been to him.

“In prison they have all those jailhouse lawyers,” he said. “These guys know the law. They know how to break it [too].”

The Juice also got choked up on the witness stand, recalling how the Sept. 13, 2007 confrontation reunited him with sentimental keepsakes — like his long-lost All-American football certificate and a picture of him with former FBI director J. Edgar Hoover.

Simpson has always maintained the armed confrontation wasn’t a robbery because he was talking back property he owned.

“I’m inhaling. Look at this stuff. Some of this stuff, I didn’t even know it was gone. I had forgotten about,” said Simpson, his voice quivering with emotion.

“My All-American certificate. As far as I knew I had it. I had it framed. Bob Hope had given it to me from Kodak and … [the] J. Edgar Hoover [picture].”

An emotional O.J. added: “These are things, you live with them in your house on the wall, you forget about them. You don’t see them. It’s wallpaper. These are things I hadn’t seen for 10 years. I was a little emotional about it.”

The former Buffalo Bills great also testified that he had no idea his pals were bringing guns the night of Sept. 13, 2007.

“There was no talk of guns at all,” he said. “Not in my wildest dreams did I think these guys would have guns.”

The Juice said he told Galanter about his plans to confront the sports memorabilia collectors and the lawyer gave him the OK to do it.